A corpora



" No Drawing.

A the alloy reduced in thickness.

.the presence of air.

Patented May 26, 1925.

UNITED STATES PATENT-OFFICE.

WESLEY J. BECK Ann JAMES A. AUIPPERLE, or MInnLErow'N, orno, ASSIGNORS 'ro- THE AMERICAN ROLLING MILL ooMPANY, or MIDDLETOWN, 01110, A coRPoRA- TION OF OHIO.

IRON ALLOY.

Application filed July 26,

To all whom it may concern:

Be it known that we, WESLEY J. BECK and JAMES A. AUPPERLE, citizens of the United States, and residents of Middletown, in the county of Butler and State of Ohio, have invented a certain new and useful Iron- Alloy, of which the followingis a full, clear, and exact description.

Our invention relates to iron alloys which have as their object the resistance to .the effects of alternate heating and cooling in If any steels, but very special alloys, are subjected .to a high temperature, say from a dark 'redheat and upward to melting point, and permitted at the same time to come in contact with the air, they will form'a crust or scale on their surface due to oxidation. This scale is heavy and on account of having a different co-eflicient of expansion from the metal will become detached therefrom upon cooling so as to fall off or become dislodged, leaving Ordinary sheet iron or sheet steel therefore deteriorates very rapidly when subjected to alternate heating and cooling, especially where high temperatures are employed, such as used for certain distillation apparatus, stoves,

. annealing boxes,-and many of the various uses in the tures. 3 a

It is our obj ect to provide a new mild steel or workablesteel for the purposes of exposure under oxjdizin conditions at high temperatures which wi 1 not be subjected to the rapid oxidation and deterioration above arts employing high temperareferred to, and we have accomplished our object by the use of silicon together with alloying-element with iron.

In. manufacturing our alloy it can 'be I produced by the acid or basic Bessemer, openhearth, "electric furnace, or crucible pro-- cesses. The refining of themetal is preferably carried to the same degree as is ordinarily practiced in the productio of .mild steel. As is the usual .practice in t e manu-- facture of ordinary steel, enough manganese can be added to the metal either in the furnace or in the ladle to produce thede 1919. Serial No. 313,611.

sired working qualities. The silicon is preferably added as a la'dle charge, otherwise the silicon, especially where oxidizingconditions have prevailed, .would have a tendency to react with the slag. The amount of silicon in the final metal may vary five-tenths of one percent, which will give some results, up to whatever percent Will admit of workin desired shape and pro uce the desired rolling and forging qualities and ductility, or as expressed in generalterms workability. We. prefer to employ from two percent to four and one-half percent, although with other metals in the alloy and special treatment the amount, may be increased above this. These percents refer to the amount of silicon in the finished roduct, andthere should be at least five-tent s percent to have a substantial amount of the silicon.

In practice, the new property imparted to steel by the addition of silicon does not give its striking results until somewhere around two percent has been reached," and the five-tenths'percent is given as the beginning, so far as we have been able to determine of the evidence of the new effect.

We have been able'to take 'two samples of silicon steel, one containing about two and four-tenths per cent of silicon, and the other about four per cent silicon, which we subjected in an electric furnace to a'tem erature of 900 'C., withgth'e current '0 air blowing over them. The samples were removed from' the furnace periodically, thoroughly cooled and pounded with a hammer in an-attempt to dislodge the protective coating. After each period of heating, cooling:i and pounding t e samples were After a hundred hours of this treatment, the samples seemed-to have changed in no respect from-their condition at the beginning of the test, and for the first sixty hours the alloy into thesheet steel,however, of like size-and gauge" to the samples mentioned and similarly treated, went to pieces at the end or sixty hours. a

So far .as physical appearance was con,-

cerned, the result of the first heat treatment was to form an'oxidized coating on the Samples whichwas hard or cementlike, and of a smooth or velvetlike finish. This finish could not be marred by the rough treatment administered, and remained, to all intents and purposes, entirely unaltered during the entire treatment. i i

Thus it may be seen from this'experiment, which is only briefly referred to, in order to illustrate the roperties which we have discovered in SllICOII steel,.that we have made a discovery of very great value in the art, and have opened up a new use to mild and inexpensive steels, whiclrhas hitherto been considered impractical. Furthermore a simple heat treatment of the alloy referred to .results in forming a flexible coating on v 1the surface of the metal,.which is more adherent'and fully as attractive in appearance as the coatings formed at high temperatures with the use of gas and supereated steam produced other processes known in the art.

' We'are aware that others have employed mild silicon steels for various purposes, but so far as'we are advised, the new property now fully noted has never before been known, and such silicon steels have never before been employed in the arts for subjection to the .oxidation under conditions of hi 'h heat.-

y high-heat, we mean such a heat as I would result in the forming of an oxidized scale onordinary sheet iron and steel 1f subjected to the air'. 'Such a heat is to be found as a condition in fuel burning appliances and accessories used with them, as a usual I thing,and thus it can be readily observed that 'the new property discovered of mild silicon steels, and the new use for said steels,

under which this property becomes of value,

' are of great importance, and that the new use occupies a large field which is quite dis-' tinct from other uses of iron and its alloys.

As a typical analysis of the alloy which will give excellent results in resisting theactioii ofjhigh temperatures under oxidizing v conditions we give the following:

v Percent. Silicon 2.400 Carbon. .120 Manganese; u .250 1 SulPhuP- 2 .040 Phosphorus; .025 ,Nitrogen l .002 y and whenu'sing highersilicon an'other'analysis which has proven satisfactory is more silicon than an Per cent.

Silicon 4000 Carbon .080 Manganese .200 Sulphur .035 Nitrogen .003 0xygen .005

These analyses are given for examples merely of a. means for gaining the 'advantage of our invention, and not as limitations of the claims that follow except where their? wording directly incorporates such details.

' The working of our alloy, together with i the heat treatments are the same as used and'known to the'art for providing the desired shapes and characteristics of ductility, malleability, or stiffness "in the finished product.

By the words iron alloys in the append ed claims, we do not intend to limit ourselves to alloys containing iron and silicon only, as the alloy might contain nickel, copper, cobalt, manganese, carbon, arsenic, or any other of the usual alloying constituents together or separately. 1

For example copper around 25% could I be present in either of theaabove formulae,

and has. been employed by us.

Having thus described our invention, what we claim as new and desire to secure by Letters. Patent, is: a

1. A workable ironalloy'which has the characteristic ofresisting destructive corrosion at high temperatures under oxidizing conditions and is fabricated into forms for use under exposure to such conditions con-i taming silicon in proportions ranging up ward from substantially two per cent to percentage'not so *high as to render it un-. workable and containing more silicon than anyother alloying metal.

2."A workable iron alloy which hasthe characteristic of resistingdestructive corrousev under exposure to such conditions contaming 51110011 in proportions sufficient to bring about formation on the surface of the metal of a' permanent protective coating of cementitiou's nature, said silicon content running from around two percent up toaround four and one half per cent and containing other alloyin .m'etal. WES E'Y J. BECl.

JAMES A UPPERLEQ 

